In a book shop, 2 staplers and 3 pens cost $19.10. Joseph bought 3 staplers and 4 pens at $26.70 from the book shop.
- Find the cost of 1 stapler and 1 pen.
- What was the cost of 1 pen?
(a)
Let 1 stapler be 1 S.
Let 1 pen be 1 P.
2 S + 3 P = 19.10 --- (1)
3 S + 4 P = 26.70 --- (2)
(2) - (1)
1 S + 1 P = 26.70 --- 19.10
1 S + 1 P = 7.60 --- (3)
Cost of 1 stapler and 1 pen = $7.60
(b)
(3)
x2 2 S + 2 P = 15.20 --- (4)
(1) - (4)
1 P = 19.10 - 15.20 = $3.90
Cost of 1 pen = $3.90
Answer(s): (a) $7.60; (b) $3.90